Question

A sample of 5 months of sales data provided the following information:

Month	1	2	3	4	5
Units Sold	99	110	81	99	91

1. Develop a point estimate of the population mean number of units sold per month (to 1 decimal).
   
2. Develop a point estimate of the population standard deviation (to 2 decimals).

Answer 1

The population size is n=5. The provided data along with the data required to compute the population mean and population variance are shown in the table below:

	X	X2
	99	9801
	110	12100
	81	6561
	99	9801
	91	8281
Sum =	480	46544

a. The population mean is computed as follows:

b.

Also, the sample variance is

Therefore, the sample standard deviation s is

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